The present invention relates to a parts assembling apparatus which is used to assemble electronic parts or the like onto a printed circuit board and the like by, for example, inserting leg portions of the electronic part or the like into assembling holes formed in the printed circuit board. More particularly, the invention relates to a novel apparatus and method which can detect the defective insertion of the leg portions of the par into the assembling holes formed in the printed circuit board.
Such a kind of conventional parts assembling apparatus has a movable arm. A holding mechanism is attached to the end of the movable arm. An electronic part such as IC part or the like is held by the holding mechanism and moved to the location over the part assembling position of the printed circuit board. Thereafter, by lowering the movable arm, the leg portions (e.g., lead pins) of the electronic part are inserted into the assembling holes formed in the printed circuit board. In this manner, the electronic part is assembled onto the printed circuit board. After the part is correctly assembled, the holding mechanism releases the electronic part and the movable arm is lifted up to be returned to the original standby position.
In this apparatus, it is necessary to check whether the leg portions of the electronic part were correctly inserted into the assembling holes of the printed circuit board or not. However, hitherto, the inserting state of the leg portions of the part into the assembling holes has been discriminated by checking whether the movable arm has been put down to a predetermined height position or not when the part is assembled.
However, according to this way of discrimination, for example, even in the case where although some of a plurality of leg portions of the electronic part were correctly inserted into the assembling holes of the printed circuit board, the remaining leg portions were bent at improper positions, the movable arm descends to the predetermined height position, so that this improper state will be misjudged to be the correct state.
When the bent leg portion comes into contact with the land portion around the assembling hole, the defective insertion of the leg portion cannot be detected by a testing device such as incircuit tester or the like. Therefore, there is such a possibility that the article including the defective electronic part is put on the market as it is. If a vibration or the like is applied to this article after that, the leg portion is removed from the land portion, causing a problem such that a failure of the article occurs or the like.